The public service broadcaster committed a "significant breach" of broadcasting rules by not revealing that the narrator of a film about the Gaza situation was the child of a Hamas official, according to regulatory body Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to accuracy".
The authority has directed the BBC to broadcast a evening declaration about its decisions.
"Since this amounts to a serious breach of our regulations, we are ordering the broadcaster to broadcast a message of our determinations against it on the BBC's second channel at 21:00, with a timing to be determined," it said.
'Potential to Erode Trust'
The authority's statement declared: "Our probe determined that the documentary's lack of disclosure that the voice's male guardian occupied a post in the Hamas-run administration was significantly deceptive.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their assessment of the voice and the information he presented.
"Trust is at the heart of the relationship between a television network and its audience, notably for a state-funded media outlet such as the BBC.
"This failing had the risk to damage the significantly high amounts of confidence that the public would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in the month of February after the boy's family links came to light, and in July an internal BBC review concluded it violated the organization's content policies on accuracy.
A corporation official stated: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a significant failing in the programme in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the regulator's ruling in complete. We will follow the penalty as soon as the schedule and wording are finalised."
